1. Field of the Invention
The present invention relates to a medical method. More particularly, the present invention relates to a method for maintaining an opening or orifice in a septum (or membrane).
2. Description of the Related Art
Noncommunicating hydrocephalus is a condition that results in the enlargement of the ventricles caused by abnormal accumulation of cerebrospinal fluid (CSF) within the cerebral ventricular system.
In noncommunicating hydrocephalus there is an obstruction at some point in the ventricular system. The cause of noncommunicating hydrocephalus usually is a congenital abnormality, such as stenosis of the aqueduct of Sylvius, congenital atresia of the foramina of the fourth ventricle, or spina bifida cystica. There are also acquired versions of hydrocephalus that are caused by a number of factors including subarachnoid or intraventricular hemorrhages, infections, inflammation, tumors, and cysts.
The main treatment for hydrocephalus is venticuloperitoneal (VP) shunts. The VP shunts are catheters that are surgically lowered through the skull and brain. The VP shunts are then positioned in the lateral ventricle. The distal end of the catheter is tunneled under the skin and positioned in the peritoneal cavity of the abdomen, where the CSF is absorbed.
However, the VP shunts have an extremely high failure rate, e.g., in the range of 30 to 40 percent. Failure includes clogging of the catheter, infection, and faulty pressure valves or one-way valves.
Another relatively newly re-introduced treatment for noncommunicating hydrocephalus is the procedure known as an endoscopic third ventriculostomy (ETV). This procedure involves forming a burr hole in the skull. A probe is passed through the burr hole, through the cerebral cortex, through the underlying white matter and into the lateral and third ventricles. The probe is then used to poke (fenestrate) a hole in the floor of the third ventricle and underlying membrane of Lillequist.
To verify that the procedure is successful, i.e., that a hole is formed in the floor of the third ventricle and the underlying membrane of Lillequist, the patient is observed with a magnetic resonance imaging (MRI) device after the probe poke. The MRI device is used to verify a flow of CSF through the hole in the floor of the third ventricle.
If the MRI device is unable to detect the flow of CSF, a determination is made that a hole in the floor of the third ventricle was not formed, and the ETV procedure is repeated.
Since the MRI device is typically located at a separate location, the ETV procedure typically requires the patient to be moved from location to location. This, in turn, increases the procedure time as well as the expense and complexity of the ETV procedure.
Further, even after successfully forming a hole in the floor of the third ventricle, the hole sometimes closes, typically within two weeks to two months after the ETV procedure. In this event, the patient will have to undergo another ETV procedure or risk serious injury or death.